OCCUPATION:WORLD WAR I
| D01.01 | Das Postgebeit OB-OST-SEINE, Postamstalten und Entwertungen by C. Noske, 1922. |
| D01.02 | Second Polish provisional Issue (1918) by J. Tislowitz. |
| D01.03 | Poland Locals by A. Hall, 123p. |
| D01.04 |
M.V.i.R - Militärverwaltung in Rumänien by F. J Mutter, published by Neue Schriftenreihe der Poststempelgilde e.V., 1999, |
| D01.05 | Die Landespost un Rumänien 1917-1918 und ihre Postanstalten by M. Althen, published by Neue Schriftenreihe der Poststempelgilde e.V., 2008, 142p. [N] |
OCCUPATION:WORLD WAR I Clippings
| D01.500CL | Official Cancels of Russian Poland and General Government Warsaw, 1915-1918 by C. Straub, clipping from The American Philatelist, 5p. |
| D01.501CL | World War 1. Ober Ost by A. Engel, clipping from GPS Specialist, March 1982, 12p. |
| D01.502CL | Deutsche Post in Nordfrankreich wahrend des Ersten Weltkriegs by R. von Scharpen, 10p. |
| D01.503CL | Censorship Markings: “Gen.-Gouv. Warschau,” 1915-1918, clipping from The American Philatelist, May 1984, 5p. |
| D01.504CL | Some German Occupation Stamps Investigated by Dr. H. Wolff, clipping from The American Philatelist, Jan. 1987, 3p. |
| D01.505CL | Poland, Scott No. 21 by S. Kronenberg, clipping from The American Philatelist, Oct. 1982, 3p. |
| D01.506CL | German Occupation of Belgium World War I - 1914-1918 by R. Yorio, clipping from Global Stamp News, October 2004. |